Projectile



March 1966 w. JUNGERMANN ETAL 3,242,855

PROJEGTILE Filed March 18, 1964 M Fla? INVENTOR lama 4m uln 7 pu ot (wh t/7r 7 4W x W United States Patent 19 Claims. (c1. 102 91 The present invention relates to projectiles.

More particularly, the present invention relates to bursting-type projectiles which are adapted to be fired from an artillery piece and which upon bursting are adapted to release granular material from the interior of the projectile.

Projectiles of this type can be filled with any desired type of material having any desired composition and composed of granular particles of the desired degree of fineness or coarseness, and of course the projectile can be either partly filled or fully filled.

In parfticular, projectiles of this type are adapted to be used for practice purposes. Certain parts are subjected to sudden forceful stresses, resulting, for example, from impacts which are encountered during the engagement of the projectile with the feeding mechanism of the artillery piece. On the other hand, the projectile is also subjected to large steady forces which do not operate by impact such as the force of gas pressure which acts on the rear of the shell of the projectile to drive it along and out of the barrel of the artillery piece. After discharging from the barrel the projectile bursts.

The shells of the projectiles of this type have already been made of thermoplastic materials. Thus, it has already been proposed to construct such shells of a plastic material which is given the desired configuration while subjected to a given pressure. However, experience has shown that such shells are not suitable for automatic weapons because the heat which is developed during the operation of such weapons is of a magnitude sufficient to start the melting of such shells with the result that the grooves of the riding in the barrel of the weapon become stopped up.

It has been proposed to manufacture shells of this type by placing them for a short time under pressure in a suitably heated mold so as to harden the exterior surface of the shell, but of course the part of the shell immediately beneath its exterior surface remains unhardened. Also, shells are known which are made up of several easily broken parts made of plastic or the like, but these structures have the disadvantage of failing to burst upon leaving the artillery piece but instead bursting only when encountering an obstruction.

It is accordingly a primary object of the present invention to provide for a projectile of the above type a shell structure which avoids the above drawbacks.

In particular, it is an object of the present invention to provide a shell structure which will be particularly suited for the particular stresses which are encountered by the shell. Thus, certain parts of the shell which are subjected to impact forces are made of a material which is highly suited to resist such forces while other parts which are subjected to relatively large but steady forces of a nonimpact nature are construction so as to readily withstand forces of this latter type.

In addition, it is an object of the present invention to provide a shell which will only burst after leaving the barrel of the weapon so that the lands and grooves of the rifiing cannot become damaged by any of the granular material which discharges from the interior of the shell after bursting thereof.

3,242,865 Patented Mar. 29, 1966 It is furthermore an object of the present invention to provide a shell which on the one hand can be easily and inexpensively manufactured from readily available plastic materials and which on the other hand is made up of components which can be inexpensively and conveniently assembled together and which will operate in a reliable way to participate not only in the operations in connection with the bursting of the shell and the containing of the granular material which is to be discharged from the interior of the shell upon bursting thereof, but also which will operate in a very reliable manner in its cooperation with the artillery piece while at the same time guaranteeing that until bursting of the shell the interior thereof remains tight so that, for example, none of the hot gas which is under pressure in the weapon can enter into the interior of the shell itself.

With these objects in view of the invention includes, in a projectile which is adapted to be fired from an artillery piece and which is adapted, after firing, to burst and to release granular material from the interior of the projectile, a shell which forms part of the projectile and which in accordance with the present invention is made up of at least two different plastic materials which have different mechanical properties. In accordance with the invention one of the plastic materials which goes into the shell is of a high tensile strength and ductility while the other of the plastic materials is made of a tough plastic which has a high resistance to impact and bending. Thus, the part of the shell which houses the granular material and which .is adapted to burst upon firing of the shell, this part being the front and intermediate portions of the shell, is made of the material which has a high tensile strength and ductility, whereas the rear part of the shell which is subjected to the forces encountered by the feeding mechanism of the weapon and the gas pressure which drives the projectile out of the artillery piece is made of the tough plastic material which has a high resistance to impact and bending.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional elevation of one embodiment of a shell according to the present invention, the shell being shown in FIG. 1 associated with a fragmentarily illustrated cartridge case;

FIG. 2 is a longitudinal sectional elevation of another embodiment of a shell according to the invention also shown connected to a fragmentarily illustrated cartridge case;

FIG. 3 is a longitudinal sectional elevation of a shell which is identical with that of FIG. 2 except that it has a different type of seam between components of the shell;

FIG. 4 is a longitudinal sectional elevation of yet another embodiment of a shell according to the invention also shown in FIG. 4 joined with a fragmentarily illustrated cartridge case; and

FIG. 5 is a transverse sectional view taken along line VV of FIG. 4 in the direction of the arrows.

There is fragmentarily illustrated in FIG. 1 a cartridge case 1 which has at its front end a neck which is shown in section in FIG. 1, and the projectile includes in addi tion to the cartridge case 1 the shell 2 the rear end of which extends into the neck of the cartridge case 1 and is joined thereto. The shell 2 has a front portion 3 which is of a substantially pointed configuration, although it has a front blunt end, and an intermediate portion 4 of the shell is of cylindrical configuration and is joined to and extends rearwardly from the front portion 3. The intermediate portion 4 of the shell is inwardly offset at the annular portion of the shell which is joined to an elongated inner rear wall 6 of the shell which has a cylindrical portion extending rearwardly from the annular portion 5 and which terminates at its rear end in a wall which extends transversely across the axis of the shell, as is apparent from FIG. 1. Thus, it will be seen that the inner rear wall portion 6 of the shell has a cylindrical portion extending forwardly from its rear end and then flaring outward-1y at the annular offset portion 5 where it is joined with the intermediate portion 4 of the shell. A rear elongated hollow cap 7 surrounds the inner Wall 6 and receives the latter in its interior, and this cap 7 of the shell has a transverse end wall located at the rear end of the shell and a cylindrical wall extending forwardly from the transverse end wall and terminating at the offset annular portion 5 of the shell.

In accordance with the present invention the front and intermediate portions 3 and 4 of the shell 2 are made of a plastic material which has a high tensile strength and ductility. While polyethylene is preferred for this plastic material, it is also possible to use instead of polyethylene, polypropylene, polybutylene, polyvinyl chloride, polyvinyl acetate, or polyvinyl alcohol. The front portion 3 and the intermediate portion 4 of the shell 2 are joined to each other along an annular seam 9 which in the illustrated example can be located substantially in a plane which is normal to the axis of the shell, and this seam 9 is preferably provided by friction welding between the parts 3 and 4.

The cap 7 at the rear of the shell has a rear end wall which is thicker than the remainder of the wall thickness of the shell, as is apparent from FIG. 1, and this cap 7 is made of a second plastic material the mechanical characteristics of which are, in accordance with the present invention, different from the mechanical characteristics of the above-mentioned plastic material used for the front and intermediate portions 3 and 4 of the shell 2. This rear cap 7 is preferably made of a thermoplastic material which is tough and has a high resistance to impact and bending, and polystyrene is preferred for this material, although it may be selected from a group which consists not only of polystyrene but also of poly methylmethacrylate, phenol formaldehyde resin, or urea formaldehyde resin. The inner wall 6 and the rear cap 7 are fixedly joined to each other by a suitable glue. The wall thickness of the shell is greater than the depth of the rifiing grooves in the barrel of the weapon.

It is to be noted that the cylindrical wall of the cap 7 extends forwardly beyond the neck of the cartridge case 1, and forwardly of the neck of the cartridge case the cylindrical wall of the cap 7 has a thickened portion 8 which serves as a guide ring for the shell. Just behind the guide ring 8 the cylindrical wall of the cap 7 has a smaller diameter than the guide ring 8, so that in this Way the rear end portion of the shell can conveniently be introduced into the neck of the cartridge case. This cap 7 is fixed with the cartridge case neck as by being glued thereto.

In the embodiment of the invention which is illustrated in FIG. 2 the front and intermediate portions of the shell are combined into a single shell member 16 which extends all the way back to a location inwardly of the front end of the neck of the cartridge case 1, and at its portion which extends into the cartridge case the Wall of the shell has a lesser thickness and diameter than its thickness and diameter just forwardly of the neck of the cartridge case, as is apparent from FIG. 2. Just in front of the neck of the cartridge case the wall of the portion 10 of the shell is thickened for a portion of the length of the shell which is sufiicient to enable this thicker wall portion 12 to act as a guide ring for the shell. A

rear cap 13 is fixed at its front end to the rear end of the shell member 10, this rear cap 13 having a thickened rear wall, as is apparent from FIG. 2, and the members 10 and 13 are connected together at the seam 14. Here again the joint between the parts 10 and 13, at the seam 14, may be made by friction welding. In the interior of the shell is located an inner wall 15 which engages the inner surface of the cap 13 and which has a lesser wall thickness than the cap 13, and it will be noted that the inner wall 15 extends across and beyond the seam 14.

\Vith this embodiment also the front and intermediate unitary part 10 of the shell is made of a plastic material of high tensile strength and ductility, such as polyethylene, and the inner wall 15 is also made of such a material, while the cap 13 is in this case also made of a tough plastic which is highly resistant to impact and bending, such as polystyrene. The rear end portion 11 of the shell part It) is joined at its interior with the inner wall 15 as by friction welding, and the cap 13 is joined by a suitable glue with the neck of the cartridge case, this cap 13 also being joined by a suitable glue or the like with the inner wall 15 as well as with the shell portion 10 at the seam 14, in this case the glued connection at the seam 14 being used instead of a friction welding connection. Tests have shown that any additional connection between the rear part 11 and the neck of the cartridge case is not absolutely essential.

With the embodiment of FIG. 3 all of the parts are identical with those of FIG. 2 except that whereas in FIG. 2 the seam 14 is located substantially in a plane which is normal to the axis of the shell, in FIG. 3 the seam 14 forms part of a cone whose axis substantially coincides with the axis of the shell, as is apparent from the illustration of the seam 14 in FIG. 3. As a result of this construction of the seam 14' a particularly strong connection between the parts is guaranteed.

With all of the embodiments described above the shell wall is made of a plastic material. In the embodiment of FIGS. 4 and 5 there is shown a shell which is provided with an outer wall 16 made of a plastic material of high tensile strength and ductility and surrounding an inner wall 17 which is made of a tough plastic material which is highly resistant to impact and bending. The cap 13 of the embodiment of FIGS. 4 and 5 corresponds to the caps 7 and 13 referred to above and it will be noted that this cap 13 of FIGS. 4 and 5 will also include in its interior an inner wall 15 which in this case also extends across the seam 14 provided in this case between the inner wall 17 of the shell and the cap 13. It will be noted that in this case also the inner wall 15 extends forwardly beyond the seam 14 while the outer wall 16 is joined at its rear end to the cap 13, extends into the depth of the cartridge case 1 to which it is glued, and has just in front of the neck of the cartridge case a thickened portion which serves as a guide ring.

The shells of the invention can be filled with a mass of particles which separate easily from each other upon bursting of the shell, and these particles may be arranged loosely within the shell or they may be pressed into the interior of the shell. It has been found to be of advantage to locate particles such as the particles 18 (FIG. 2) which are of a relatively small specific weight, at the front of the shell, approximately at the front third thereof, while at the rest of the inner space of the shell, and in particular the intermediate ortion thereof, there is a filling material 19 composed of particles which have a heavier specific weight than the particles of the mass 18.

As was mentioned above the projectile of the invention is particularly suited for practice purposes. In particular, it is to be noted that with the structure of the invention when the firing of the projectile takes place the gases which develop cannot have access to the interior of the shell so that it is not possible to have premature bursting of the shell of the invention. With the use of the different plastic materials having the different mechanical properties as described above, the rear end of the shell can withstand the very high powder pressure while the walls of the front and intermediate portions of the shell will only burst after the shell has left the weapon. As has been pointed out above when the shell is to be used with a granular filling material, tests have shown that it is of advantage to locate in the front portion of the shell a. granular material of a relatively light specific weight and having particles which easily separate from each other while in the remainder of the interior of the shell the filling mass can be made up of particles of a greater specific weight. The construction of the invention has proved to avoid in a very reliable manner any contact between such a granular filling material and the rifling of the weapon since with the structure of the invention the filling material only leaves the projectile after the latter has been fired from the artillery piece and thus none of the particles can engage the lands or grooves of the barrel rifiing It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of projectiles differing froln the types described above.

While the invention has been illustrated and described as embodied in shells for projectiles, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without-further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A bursting-type projectile adapted to be fired from an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising an elongated hollow shell having a forward portion and a rearward portion and being made up of at least two plastic materials of different mechanical properties, one ofsaid materials having a high tensile strength and ductility and the other of said materials being a tough plastic of high resistance to impact and bending, said forward portion being made up at least partly of the mate rial having high tensile strength and ductility, and said rearward portion being made up at least partly of said plastic of high resistance to impact and bending so as to better withstand impact forces encountered upon firing of said projectile.

2. A bursting-type projectile adapted to be fired from an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising a multipartite elongated hollow shell which includes a front portion, an intermediate portion, and a rear inner wall portion having an end wall, all made of a plastic material of high tensile strength and ductility, and a rear cap in which said rear inner wall portion is located, said rear cap having a rear wall abutting said end wall in face-to-face relationship, and said rear cap being made of a tough plastic material having a high resistance to impact and bending.

3. A projectile as recited in claim 2 and wherein said shell includes within said front and intermediate portions an interior wall made of a tough plastic material of high resistance to impact and bendin 4. A bursting-type projectile adapted to be fired from an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising a multipartite elongated hollow shell of said materials being a tough plastic which is highly,

resistant to impact and bending, and said shell having a rear cap made from said other material of high resistance to impact and bending, said rear cap being provided with an integral rear wall at the rear end of the shell, and said rear wall having a wall thickness which is substantially greater than the wall thickness of the remainder of the shell.

5. A bursting-type projectile adapted to be fired from an artillery piece which has in the interior of its barrel a rifling provided with grooves of predetermined depth, said projectile upon bursting releasing granular material from the interior of said projectile, and said projectile comprising a multipartite elongated hollow shell made up of at least two different plastic materials of different mechanical properties, one of said materials having a high tensile strength and ductility and the other of said materials being a tough plastic which is highly resistant to impact and bending, at least a rear portion of said shell being made from said other material highly resistant to impact and bending, and said shell having a wall thickness which is greater than the depth of said grooves.

6. A bursting-type projectile adapted to be fired from' an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising a multipartite elongated hollow shell made up of at least two different plastic materials of different mechanical properties, one of said materials having a high tensile strength and ductility and the other of said materials being a tough plastic which is highly resistant to impact and bending, and said shell including a rear cap made from said other material of high resistance to impact and bending, said rear cap being provided with an integral rear wall located at the rear end of the shell and a cylindrical wall extending forwardly from said rear wall.

7. A projectile as recited in claim 6 and wherein said rear cap is fixed to the interior of the neck of a cartridge case, said cylindrical wall of said rear cap extending forwardly beyond said neck of said cartridge case and having forwardly of said neck of said cartridge case a Wall thickness greater than that of the part of the cylindrical wall which is located within said neck of said car tridge case, andsaid portion of said cylindrical wall which extends forwardly of said neck of said cartridge case being adapted to act as a guide ring for the shell.

8. A bursting-type projectile adapted to be fired from an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising an elongated hollow shell made up of at least two different plastic materials of different mechanical properties, one of said materials having a high tensile strength and ductility and the other of said materials being a tough plastic which has a high resistance to impact and bending, said shell having front, intermediate, and rear portions, at least the rear portion of said shell being made from said other material of high resistance to impact and bending, and a cartridge case having a neck into which said rear portion of said shell extends and to which said rear portion is fixed, said intermediate portion of said shell having just in front of said neck of said cartridge case a wall thickness which is greater than the wall thickness of the remainder of the intermediate portion of said shell and which serves as a guide ring for the shell.

9. A bursting-type projectile adapted to be fired from an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising an elongated hollow shell made up of at least two different plastic materials of different mechanical properties, one of said materials having a high tensile strength and ductility and the other of said materials being a tough plastic which has a high resistance to impact and bending, said shell including a rear cap having a rear Wall and a cylindrical Wall extending forwardly from said rear wall and said shell including an inner rear wall portion which extends along the inner surface of said cap, which is cylindrical at its portion which is surrounded by the cylindrical wall of said cap and which at the front end of said cylindrical wall of said cap is directed outwardly to join the remainder of said shell which extends forwardly from said cap.

10. A bursting-type projectile adapted to be fired from an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising an elongated hollow shell made up of at least two ditferent plastic materials of different mechanical properties, one of said materials having a high tensile strength and ductility and the other of said materials being a tough plastic which has a high resistance to impact and bending, and said shell including an elongated intermediate portion having a rear edge and a rear cap made from said other material of high resistance to impact and bending, and said rear cap having a rear wall at the rear end of the shell and a cylindrical wall extending forwardly from said rear wall and having a front edge which abuts against the rear edge of said intermediate portion of said shell.

11. A projectile as recited in claim 10 and wherein said intermediate portion of said shell forms part of an inner shell wall and said shell having an outer shell wall surrounding said inner shell wall.

12. A projectile as recited in claim 10 and wherein said intermediate shell portion which abuts against said cap is part of an exterior wall of the shell.

13. A bursting-type projectile adapted to be fired from an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile comprising an elongated hollow shell made up of at least two different plastic materials of different mechanical properties, one of said materials having a high tensile strength and ductility and the other of said materials being a tough plastic which is highly resistant to impact and bending, said shell including elongated front and intermediate portions, said intermediate portion terminating in a rear edge, and a rear cap having a rear wall at the rear end of the shell and a cylindrical wall extending forwardly from said rear wall and having a front edge abutting said rear edge and joined thereto to form a seam therewith, said shell having an inner rear wall located within said rear cap and extending forwardly over and beyond said seam.

14. A projectile as recited in claim 13 and wherein said seam is located substantially in a plane which is normal to the axis of said shell.

15. A projectile as recited in claim 13 and wherein said seam forms part of a cone whose axis substantially coincides with the axis of the shell.

16. A projectile as recited in claim 13 and wherein said portions are fixed to each other by glue.

17. A projectile as recited in claim 13 and wherein said portions are fixed to each other by friction welding. 18. A bursting-type projectile adapted to be fired from. an artillery piece and upon bursting to release granular! material from the interior of the projectile, said projectile comprising an elongated hollow shell made up of at least two plastic materials of difierent mechanicalproperties, one of said materials being polyethylene having a high tensile strength and ductility, and the other of said materials being polystyrene having high resistance to impact and bending.

19. A bursting-type projectile adapted to be fired from.

an artillery piece and upon bursting to release granular material from the interior of the projectile, said projectile; comprising an elongated hollow shell made up of at. least two plastic materials of different mechanical prop erties, one of said materials being selected from the- References Cited by the Examiner UNITED STATES PATENTS 2,986,091 5/1961 Ferguson 1OZ-92.5 3,170,405 2/1965 Jun'germann et al. 102-91 FOREIGN PATENTS 577,930 6/1946 Great Britain.

BENJAMIN A. BORCHELT, Primary Examiner.

FRED C. MATTERN, JR., Examiner. 

1. A BURSTING-TYPE PROJECTILE ADAPTED TO BE FIRED FROM AN ARTILLERY PIECE AND UPON BURSTING TO RELEASE GRANULAR MATERIAL FROM THE INTERIOR OF THE PROJECTILE, SAID PROJECTILE COMPRISING AN ELONGATED HOLLOW SHELL HAVING A FORWARD PORTION AND A REARWARD AND BEING MADE UP OF AT LEAST TWO PLATIC MATERIAL OF DIFFERENT MECHANICAL PROPERTIES, ONE OF SAID MATERIALS HAVING A HIGH TENSILE STRENGTH AND DUCTILITY AND THE OTHER OF SAID MATERIAL BEING A TOUGH PLASTIC OF HIGH RESISTANCE TO IMPACT AND BENDING, SAID FORWARD PORTION BEING MADE UP AT LEAST PARTLY OF THE MATERIAL HAVING TENSILE STRENGTH AND DUCTILITY, AND SAID REARWARD PORTION BEING MADE UP AT LEAST PARTLY OF SAID PLASTIC OF HIGH RESISTANCE TO IMPACT AND BENDING SO AS TO BETTER WITHSTAND IMPACT FORCES ENCOUNTERED UPON FIRING OF SAID PROJECTILE. 